Generally, a technology for storing a different material in a closure associated with a PET bottle is well known. However, such a technology is not applied to a flexible container as it is difficult to apply the same to spouts having different sizes.
Therefore, a secondary material is filled in the flexible container through the spout. However, it is troublesome to mix secondary material through the spout having a small diameter hole.
In addition, a barrier is installed in the pouch container to store the secondary material. In use, the barrier is removed so that the secondary material can be mixed with a primary material. In this case, it is however difficult to remove the barrier, making it difficult to effectively mix the secondary material with the primary material.